Data input system for an electrical machine

ABSTRACT

An input system for an electrical machine including a mechanism for connection between each key and a shutter therefor in the keyboard of the console of the machine. The shutter interrupts light from one or more sources to one or more photocells to provide a coded input for the machine. The shutter of each key is moved by the mechanism by a snap action to avoid the need for interlocked keys. Simultaneous inputs from two keys are avoided because the shutter is moved by the mechanism at a substantially greater rate than it is possible to actuate a key manually.

Cramer et al.

3,777,155 Dec 4, 1973 DATA INPUT SYSTEM FOR AN ELECTRICAL MACHINE Inventors: Bernhard Cramer,

Pforzheim/Sonnenberg; Wolfgang Andrich, Grunbach, both of Germany International Standard Electric Corporation, New York, N.Y.

Filed: July 10, 1972 Appl. No.: 270,221

Assignee:

Dodsworth et al.... 250 219 DD Primary ExaminerJames W. Lawrence Assistant ExaminerT. N. Grigsby Attorney-C. Cornell Remsen, Jr. et al.

[57] ABSTRACT An input system for an electrical machine including a mechanism for connection between each key and a shutter therefor in the keyboard of the console of the machine. The shutter interrupts light from one or more sources to one or more photocells to provide a coded input for the machine. The shutter of each key is moved by the mechanism by a snap action to avoid the need for interlocked keys. Simultaneous inputs from two keys are avoided because the shutter is moved by the mechanism at a substantially greater rate than it is possible to actuate a key manually.

3 Claims, 4 Drawing Figures DATA INPUT SYSTEM FOR .AN ELECTRICAL MACHINE BACKGROUND OF THE INVENTION The present invention relates to a photoelectric keyboard for data input devices or the like in which, by operation of a key, a coded shutter mask is moved to intercept light beams extending parallel to each other and directed to photocells.

Keyboards of the above-described kind are well known, e .g., from the German Petty Pat. No. 1,816,744 and the German printed application No. (DAS) 1,252,729. In these and all other known designs, the shutter masks are directly linked with one key each, so that withthe operation of the keys, the associated shutter masks move to intercept the light beams and remain there as long as the keys are depressed. In order to pre- 7 vent any superposition of two characters entered in close succession, which would inevitably result in a falsification of the code, such keyboards are provided with so-called key locks, which lock the other keyboard elements for the duration of the operation of one key. 1

These locks, which operate mostly on a mechanical basis, hamper the individual manner of writing, and particularly the so-called Legato-Writing (depressing the next key before releasing the previous one). Keyboards with key locks are thus more difficult to operate and require special knowledge. In addition, a keyboard using key locks is very expensive.

SUMMARY OF THE INVENTION The invention is characterized in that the keys of the keyboard are indirectly connected via snap mechanisms with the associated shutter masks, and that, via said snap mechanisms, the shutter masks move and intercept the light beams for very short periods of time, independently of the kind and duration of the respective key operation.

Some outstanding advantages achieved by the invention are that, even if the keys are operated in quick'succession, any superposition of entered characters is practically excluded. Any special key lock can thus be dispensed with at a substantial cost saving. This makes possible an individual manner of writing and insure ease of operation. v

The above-described and other advantages of the present invention will be better understood from the following detailed description when considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be explained in more-detail with reference to one embodiment thereof and in connection with the accompanying drawing, in which:

FIG. 1 is a side elevational view of a keyboard module with the shutter mask being in one position of rest;

FIG. 2 is a side elevational view of the module with the shutter mask being in the other position of rest;

FIG. 3 is a sectional view of the module taken on the line 3-3 shown in FIG. 2; and

FIG. 4 is a perspective view of the console including a keyboard.

DESCRIPTION OF THE PREFERRED EMBODIMENT The basic structure of photoelectric keyboards is well known, so that it need not be specially described herein.

A keyboard consists of several modules, which are arranged side by side, abutting on each other at the ends shown in FIG. 1. Located at one end of this constructional unit is a lighting device which consists of one or more light sources and whose light is combined, via combinations of lenses, into light beams which fall through aligned aperture masks 8 of the keyboard modules, parallel to each other, on photocells arranged at the other end of constructional unit..lnterrogated at a certain instant, the photoelectric currents of these cells represent, in coded form, the character entered by operating a corresponding key, which character is evaluated or processed in known manner by subsequently arranged electronic circuits.

In the embodiment of a keyboard module as illustrated herein by way of example, the vertically shiftable key 1 is indirectly connected via a snap mechanism, de-

scribed in more detail in the following, with a horizontally adjustable shutter mask 7.'The coding of the shutters 7 in accordance with the associated character is effected in known manner by breaking or cutting out the shutters not required (broken lines), so that only certain light beams are momentarily interrupted by the remaining shutters 7a in the course of the key operation.

To achieve an exact switching behavior and prevent any kind of trouble caused by scattered light and reflection, each key module has a stationary aperture mask associated-with it, which is arranged in the direction of the light beams in front of the associated shutter mask 7. The aperture mask 8 is provided, in accordance with the bit number of the code used, with a number of equally spaced apertures 8a, through which the light rected tip standing over the center of rotation of an operating element4 which is pivotally mounted on a bolt 5 fixed to key "shank la. Held in one (FIG. 1) or the other (FIG. 2-) position by a dead-center spring-6 acting above the center of rotation, the operating element 4 has two engaging depressions 4a located symmetrically to the center line and on a level with the center of rotation.- Engaging depressions 4a are engaged by pawl 3 when the key 1 is operated. At the lower end, the operating element 4 is provided with an operating pin 4b, which moves into engagement with a recess 7c of the shutter mask 7. Through the dead-center spring 6, the associated shutter mask 7 forces the shutter mask 7 via the pin'4b against stops A and B.

If the key 1 of FIG. 1 is operated, the pawl 3 moves vertically downwards, turning to the right into the engaging depression 4a of the operating element 4. As the key 1 is pressed further downward, the operating element 4 turns clockwise, overcoming the relatively weak effect of the dead-center spring 6. In the process, the operating pin-4b moves away from the right stop position in the recess of the shutter mask 7. Up to this time, the associated shutter mask 7 has not yet changed its position, so that any inadvertent depression of a key down to this depth produces no effect. Only when the operating element 4 has been swivelled so far that the point of application of the force of the spring 6 lies on the right of the center of rotation of the operating element 4 does the direction of effect of the dead-center spring 6 change. The result of this is that the operating element 4, under the influence of the spring 6, springs into the position shown in FIG. 2, taking along the associated shutter mask to the left via the pin 4b. The stroke of the mask 7 corresponds exactly to the spacing of the apertures 8a in the aperture mask 8. Consequently, the light beams are interrupted by the remaining shutters 7a only for a very short period of time, the kind and duration of the key operation having no influence. Thus, it is insured that a superposition and, consequently, fa1- sification of characters is practically excluded even if the characters are entered in close succession. The use of key locks is thus also made unnecessary.

As mentioned hereinbefore, by the shutter 7b, which is narrower than the shutter 7a, a narrow strobe pulse is produced at the moment the shutters are shifted. This pulse, which occurs in the middle of the interruption of the other light beams, activates subsequent electronic circuits only for its duration, whereby time variations are eliminated.

As the operated key 1 is released, it returns to its original position under the effect of the spring 2, with the pawl 3 also returning to its normal position under the effect of the spring 30. Thus, the original position shown in FIG. 2 has been reached, from which, if the key 1 is operated anew, the operating element 4 is now turned counterclockwise, and, at the moment the direction of effect of the dead-center spring 6 is changed, resets the shutter mask to the right.

The horizontally adjustable shutter mask 7 may also be advantageously designed as a circular mask which is mounted so as to be rotatable throughout an angular path following from the spacing of the apertures of the likewise circular aperture mask.

What is claimed is:

1. In an electrical machine, the combination comprising: a console including a frame having a keyboard, said keyboard including a set of a plurality of independently operable keys that may be manually operated simultaneously; at least one light source and one photosensitive device for each key of said set, each light source and device being fixed relative to said frame in a manner such that the source for each key can illuminate the device therefor; a mask fixed relative to said frame intermediate each corresponding source and device, each mask having an aperture therethrough through which light from a corresponding source may pass to illuminate a corresponding device; a shutter movable relative to each corresponding mask into and out of intercepting relation with light passing through said aperture, each of said keys being manually movable relative to said mask; and means responsive to movement of and connected from each key of said set to move a corresponding shutter into and out of said light intercepting relation at a speed substantially greater than the manual speed at which each corresponding key is moved.

2. The invention as defined in claim 1, wherein said devices are photocells.

3. The invention as defined in claim 2, wherein each key is slidable axially relative to said frame, a first spring mounted between said frame and each key to bias each in an axial direction, a member rotatable on each key, a second spring connected from each member at a first point spaced from the rotational axis thereof to a second point fixed relative to said frame, said first point being rotatable over center, each member having a notch, a pawl carried by each key to engage the notch in each corresponding member to rotate it past center, each said member having a projection to engage and to move said shutter with it, said mask having a pair of stops to limit the travel of said shutter.

III =8 

1. In an electrical machine, the combination comprising: a console including a frame having a keyboard, said keyboard including a set of a plurality of independently operable keys that may be manually operated simultaneously; at least one light source and one photosensitive device for each key of said set, each light source and device being fixed relative to said frame in a manner such that the source for each key can illuminate the device therefor; a mask fixed relative to said frame intermediate each corresponding source and device, each mask having an aperture therethrough through which light from a corresponding source may pass to illuminate a corresponding device; a shutter movable relative to each corresponding mask into and out of intercepting relation with light passing through said aperture, each of said keys being manually movable relative to said mask; and means responsive to movement of and connected from each key of said set to move a corresponding shutter into and out of said light intercepting relation at a speed substantially greater than the manual speed at which each corresponding key is moved.
 2. The invention as defined in claim 1, wherein said devices are photocells.
 3. The invention as defined in claim 2, wherein each key is slidable axially relative to said frame, a first spring mounted between said frame and each key to bias each in an axial direction, a member rotatable on each key, a second spring connected from each member at a first point spaced from the rotational axis thereof to a second point fixed relative to said frame, said first point being rotatable over center, each member having a notch, a pawl carried by each key to engage the notch in each corresponding member to rotate it past center, each said member having a projection to engage and to move said shutter with it, said mask having a pair of stops to limit the travel of said shutter. 